218205 has 24 divisors (see below), whose sum is σ = 408408. Its totient is φ = 107136.

The previous prime is 218191. The next prime is 218213. The reversal of 218205 is 502812.

It can be written as a sum of positive squares in 4 ways, for example, as 4761 + 213444 = 69^2 + 462^2 .

It is not a de Polignac number, because 218205 - 2⁷ = 218077 is a prime.

It is a super-2 number, since 2×218205² = 95226844050, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 399 + ... + 771.

It is an arithmetic number, because the mean of its divisors is an integer number (17017).

2²¹⁸²⁰⁵ is an apocalyptic number.

It is an amenable number.

218205 is a deficient number, since it is larger than the sum of its proper divisors (190203).

218205 is a wasteful number, since it uses less digits than its factorization.

218205 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 397 (or 394 counting only the distinct ones).

The product of its (nonzero) digits is 160, while the sum is 18.

The square root of 218205 is about 467.1241804917. The cubic root of 218205 is about 60.2034758463.

The spelling of 218205 in words is "two hundred eighteen thousand, two hundred five".